1. Field of the Invention
The present invention, relates to a panel unit that is mounted on an image pickup apparatus including a digital video camera, and an electronic apparatus including a mobile communication apparatus, such as a cellular phone, a smartphone, and a tablet device, and reduces the influence of static electricity, and an electronic apparatus including the panel unit.
2. Description of the Related Art
Touch panels mounted on display panels of display units of image pickup apparatuses, such as digital video cameras, and mobile communication apparatuses, such as smartphones, are largely classified into two types: resistance film-type touch panels and electrostatic capacity-type touch panels.
In general, in the above-mentioned two types of touch panels, a frame area is required to be provided along an outer periphery of a position detection area in which position detection can be performed, as shown in FIG. 21.
The resistance film-type touch panel includes an upper electrode and a lower electrode fixed with a fixed spacing therebetween, and when an operator presses the upper electrode, the upper electrode is deformed to cause conduction between the upper electrode and the lower electrode. The position of a pressed point is detected from this conduction. Further, to hold the upper electrode and the lower electrode with the fixed spacing therebetween, a support structure, such as a spacer, is required to be provided on the outer periphery of the position detection area, and the support structure and interconnection cables for signal detection are arranged on the frame area shown in FIG. 21 (see Japanese Patent Laid-Open Publication No. 2000-305715).
On the other hand, the electrostatic capacity-type touch panel performs position detection by detecting a change in electrostatic capacity between a fingertip of the operator and a conductive film (see Japanese Patent Laid-Open Publication No. 2010-39515).
Further, in general, to transmit a signal output from the touch panel e.g. to a drive circuit mounted on another substrate, the above-mentioned two types of touch panels nave a interconnection member connected thereto, and the interconnection member is provided in a manner protruding from the frame area.
The interconnection member is generally in the form of an FPC (flexible printed circuit board) or the like. One end of the interconnection member is fixedly attached to a connection part of the conductive film of the touch panel for electrical and mechanical connection thereto, and the other end of the interconnection member has a terminal section thereof connected to a circuit board on which a drive circuit and so forth are mounted, using a connector or by soldering.
By the way, when using the touch panel, a finger, a pen, or the like, which touches the touch panel, is often electrostatically charged. For this reason, when the finger, the pen, or the like, is brought into contact with the surface of the touch panel, noise generated by the charged static electricity is transmitted to the touch panel and the circuit board via an exposed portion of the conductive film and the interconnection member, which may degrade the accuracy of position detection or cause a malfunction.
As a countermeasure against static electricity, there has been proposed a technique for reducing the influence of static electricity by disposing a conductor, which functions similar to a lightning rod, on the exposed portion of the conductive film, and further connecting the conductor to an electrically conductive casing to thereby guide static electricity toward the casing (see Japanese Patent Laid-Open Publication No. 2002-323691).
However, in Japanese Patent Laid-Open Publication No. 2002-323691, static electricity charged e.g. on the finger or the pen is applied from the front side of the touch panel. Therefore, the conductor which functions similar to the lightning rod is required to be arranged on the front side of the conductive film and the interconnection member, which increases the size of the display unit, and in turn, the size of the electronic apparatus. Further, recent digital video cameras, mobile communication apparatuses, etc. employ a flat panel-type display unit which is designed to form a surface of the touch panel and a surface of an external cover such that they are flush with each other. It is difficult to dispose the above-mentioned conductor, which functions as a conductor rod, on such a display unit.